International Business Times —
A new study found that humans are releasing carbon emissions at a significantly faster rate than the past event that led to a major marine life die-off.
As the name suggests, the Paleocene-Eocene Thermal Maximum (PETM) some 55 million years ago was a period of maximum temperature that lasted for about 100,000 years. The period was characterized by the highest global temperatures during the Cenozoic Era, which covers 65 million years ago until the present, and it is considered to be the closest natural analog to modern human carbon dioxide emissions.
A news release from Columbia University explains that the world was already warmer than it is today even before PETM but, rising carbon emissions during PETM led to a further 5 to 8 degrees Celsius of warming. The carbon emissions at the time were from natural sources, for instance volcanic activity, widespread fires or a comet collision, but the exact cause and the amount of carbon released had been unclear.
And when the oceans then absorbed the massive carbon emissions, they turned acidic and deadly to many marine species.